On March 30, 2026<\/strong>, Google Quantum AI published a whitepaper that shook the crypto markets well beyond research circles. Titled “Securing Elliptic Curve Cryptocurrencies<\/a> against Quantum Vulnerabilities”, co-authored with teams from Stanford and the Ethereum Foundation, the document demonstrates that breaking the elliptic curve cryptography securing Bitcoin<\/a> and Ethereum<\/a> would require fewer than 500,000 physical qubits<\/strong>, representing a reduction of about 20 times<\/strong> compared to previous estimates that projected several million.<\/p>\n\n\n\n The described quantum machine could crack a Bitcoin<\/a> private key in about 9 minutes<\/strong> once the public key is exposed, giving an attacker roughly a 41% chance<\/strong> of beating the network’s 10 minute<\/strong> confirmation window. This paves the way for so-called “on-spend” attacks: targeting an active transaction in the mempool before it is confirmed in a block.<\/p>\n\n\n\n